TF-004 Read, generate and modify configuration Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  variable "enabled" { type = bool default = true }

  Why this is correct

  This variable declaration is valid because the `type` constraint is correctly set to `bool`, and the `default` value provided, `true`, is a literal boolean value. Terraform successfully validates that the default value's type precisely matches the explicitly declared `bool` type, ensuring strict type consistency for the variable. This configuration allows the variable to accept only `true` or `false` values.

• ✓

  variable "tags" { type = map(string) default = {} }

  Why this is correct

  This variable declaration is valid as it correctly specifies `map(string)` as its type, indicating a map where all values must be strings. The provided `default` value, `{}`, is an empty map literal, which perfectly conforms to the `map(string)` type constraint. Terraform allows an empty map as a valid default for any map type, as it contains no elements that would violate the value type constraint.

• ✓

  variable "region" { type = string default = "us-east-1" }

  Why this is correct

  This declaration is valid because the `type` is explicitly set to `string`, and the `default` value `"us-east-1"` is a literal string. Terraform successfully validates that the default value's type aligns perfectly with the declared `string` type constraint. This ensures that if no value is explicitly provided for `region` during execution, it will default to the specified string, maintaining type safety throughout the configuration.

• ✗

  variable "names" { type = list(string) default = "name" }

  Why it's wrong here

  This variable declaration is invalid because of a fundamental type mismatch between the declared `type` and the `default` value. The `type` is specified as `list(string)`, which expects a collection of strings, such as `["name1", "name2"]`. However, the `default` value provided, `"name"`, is a single string literal, not a list. Terraform will raise a type conversion error, as a string cannot be implicitly converted to a list of strings.

• ✗

  variable "count" { type = number default = "1" }

  Why it's wrong here

  This variable declaration is invalid due to a critical type mismatch. The `type` is explicitly declared as `number`, which expects an integer or float value without quotes, like `1` or `1.0`. However, the `default` value provided, `"1"`, is a string literal because it is enclosed in double quotes. Terraform will fail to validate this, as a string cannot be automatically coerced into a number type for a default value, leading to a configuration error.

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